Zaki,

Ecotect utilizes the Daylight Factor and the Design Sky to provide you with daylight levels for the worst case scenario.
Now, the daylight factor isn't influenced by orientation, or time of the day as it assume an overcast sky - no sun - for worst case scenario.
To get the daylight levels, it simply multiply this daylight factor by the Design Sky.

The only things affecting the daylight factor is the geometry of your model (such as the size of your windows), as well as the reflectivity of your material and any other obstructions.

Give RADIANCE a try as it can give you light level for anytime of the year.

Best,
Olivier

Hi Oliver,

Thanks for your feedback and suggestions on this.

I went through Ecotect help and realized the difference between performing daylight analysis in the standard way in Ecotect (i.e. over the standard analysis grid) and in Radiance. I realize now that Radiance makes sense of the sun location and building orientation and produces light levels at the chosen time of the year.

I was also able to display light levels results in Radiance back into Ecotect analysis grid. I did the following so that to share that with users in this forum:
1)I displayed the analysis grid in my model.
2)In the ‘Analysis Grid’ tab clicked on ‘Select Grid Nodes’ which will allow the user to select the grid nodes using a window selection method.
3)Then selected from the menu Calculate/Lighting Analysis.
4)In step 1 of the lighting analysis wizard I selected the bottom option ‘Export to Radiance for more detailed analysis’
5)In step 2 select the option ‘Surface and/or Point analysis’
6)In step 3 of the radiance analysis wizard I selected option ‘Sunny Sky (Summer)’ to perform light level calculation based on a localized sun.

After the radiance calculation is finished in the DOS command a message will come up asking you to loaded the results into the analysis grid. I did that following these steps:
1)In the ‘Analysis Grid’ tab click on the ‘Grid Management’ button.
2)In the analysis grid management window click on the ‘Manage Grid Data’ tab.
3)Click on ‘Merge File’ button and select ‘overwrite’ from the floating popup menu. This will allow the user to load *.DAT file that contains the radiance results creates in the last phase as explained above.
4)Browse to find the *.DAT file. As a result this will display the analysis results from Radiance back on to the analysis grid.

Zaki

Oliver and Zaki -

I was working on a related issue where I got strange results from Ecotect's daylighting grid. I did the same test again using Radiance and the results were much more in line with what I was expecting. In both cases, I used an overcast sky so there's no differentiation between the north and south side, but the values that Ecotect was giving me seemed way to high. If you have any suggestions, please let me know. I am concerned that my settings are set to lux when they should be footcandles...eveything is off by a factor of ten. See attached for details.

Dear Oliver,

Nice to meet you.
I am working with Radiance as well and there are some questions I am trying to sort it out.
Could you please to help me?
I am trying to run a forward raytracing analysis in Radiace, and using Ecotect for it.
I cannot find how to set a forward raytracing analysis in Ecotect and export that information to Radiance.
Is there a way to solve the problem?
Thank you for your attention,
Rodrigo